Staff across all of Rupert Murdoch's News International newspapers have been warned not to delete or destroy documents relating to any of the phone-hacking investigations now under way.
In an email sent to employees over the weekend, the company reveals it has suspended all automatic deletion of files and destruction of documents.
The memo shows News Corp's fears that journalists from its other papers might get sucked into the phone-hacking scandal, given the company's insistence that it was solely an issue for the News of the World.
The email, sent from News Corp's new Management and Standards Committee, also raises questions about why such a policy has only just been implemented, given that the company has been aware of the extent of the allegations against it for some time.
"It is very important that all News International employees take immediate steps to preserve and retain all documents that may be relevant to these issues," it reads. "We apologise that this is necessary but it is an important step the company must take in order to comply with the various investigations."
The email goes on to warn staff that "all types of electronic and hard copy data or communications, including memoranda, letters, emails, reports, presentations, handwritten notes, tapes and any other recorded information or computer media" are covered by the edict.
It adds: "Please suspend any automatic deletion or discarding of any documents, whether electronic or paper, including emails or drafts of documents... If you are uncertain whether a document is relevant... you should preserve it."
The company also confirms that its current policy towards the deletion of documents has been suspended. "Given the current circumstances you should be aware that all policies requiring the destruction of such documents or overwriting of any electronic material will be suspended immediately," it said.
The News of the World newsroom has already been sealed and staff refer to it as a "crime scene". All News Corp staff will be spoken to in the coming days over the way they deal with emails.
News Corp's Management and Standards Committee is being run on a day-to-day basis by Will Lewis, public-relations man Simon Greenberg and Jeff Palker, general counsel for News Corp Europe and Asia. It is being overseen by Joel Klein, a News Corp director and former legal adviser to the White House.
Yesterday, The New York Times reported concerns about Mr Klein's role as an independent adjudicator given his close relationship with the Murdochs. He sat behind them when they gave evidence to MPs on Tuesday and was initially hired by the company to push its educational publishing arm.
Lawyers and experts in corporate governance said News Corp should have hired outside legal counsel to oversee the inquiry, rather than use an executive director. "That is not standard practice," said Charles Elson, an expert on corporate governance at the University of Delaware. "You cannot be seen as objective if you are inside."